1. Field of the Invention
This invention relates to the field of security systems, and in particular to security systems that adaptively create and modify security rules and parameters based on prior events.
2. Description of Related Art
Security systems are common in the art. With the advent of computers and data base systems, inventory security systems are also becoming prevalent. PCT patent application WO 97/15031, "Article Inventory Tracking and Control System", published Apr. 24, 1997, discloses a system wherein each inventoried article is uniquely identified via a "marker". Users associated with the secured facility are also uniquely identifiable, via for example an identification card with a magnetic strip containing a unique identifier. The user places the inventoried article into a "check-out/check-in" device, along with the user's identification card. If the user is authorized to remove the device from the secured facility, the "marker" is switched to an inactive state. In a retail environment, the user is granted authorization to remove the device after a debit is registered to an account that is associated with the user's identification, such as a user's credit card account. Each egress from the secured facility contains a sensor for active markers. If an inventoried item's marker has not been inactivated, by the check-out/check-in device, the sensor will detect the active marker, and an alarm event is triggered to prevent the unauthorized removal of the item. In like manner, a user can return an inventoried item to the secured facility by presenting the item to the check-out/check-in device. When the inventoried item is checked in, the device reactivates the item's marker, and updates a database file to reflect the user's return of the inventoried item. A typical application of the system includes an automated check-out/check-in process for a lending library, a video rental store, and so on. U.S. Pat. No. 4,881,061, "ARTICLE REMOVAL CONTROL SYSTEM", issued Nov. 14, 1989, operates similarly.
U.S. Pat. No. 5,886,634, "ITEM REMOVAL SYSTEM AND METHOD", issued Mar. 23, 1999, and incorporated by reference herein, provides a less intrusive system that uses radio-ID tags that are attached to people and items. A database associates each identified item with one or more people who are authorized to remove the item. When an item is detected at an exit without an authorized person, an alert is generated. The system also interfaces with inventory control systems, and can provide the capabilities discussed above, such as an automated check-in, check-out system.
In the prior art systems, the database of authorizations for each secured item in the inventory must be kept up to date. Because of the overhead that is typically associated with maintaining an inventory security system, the rules and processes that are enforced are relatively static and simple. Such a system may be well suited for a library or retail environment, wherein a convenience is provided relative to a conventional manned check-out station, but the same system may not be well received in an environment that is not normally secured.
In an office or laboratory environment, for example, employees are not typically subjected to security processes, even though theft of property does occur in these environments. This lack of security may be based on a reluctance to demonstrate a lack of trust to the employees; it may be based on the logistic difficulties, such as exit queues, caused by requiring each employee to check out inventoried items each time the items are removed from the secured facility; it may be based on the anticipated annoyances that false alarms may trigger; and so on. Similarly, in many large organizations, or large facilities, it may be infeasible to attempt to map each identified item in the facility with a set of the individuals who are authorized to remove the item.